Magnetic transducing heads typically include both a write element and a read element. The write element is configured to generate magnetic fields that align magnetic moments of the recording data to represent bits of data.
To write data to a recording medium, an electric current can be applied to conductive coils to induce a magnetic field in the medium under a write pole. The write pole can define the track width of the data written. More specifically, in perpendicular recording the magnetic signals can be conducted through the trailing edge of the write pole in a manner that orients the magnetic moments of the recording medium perpendicularly to the surface of the recording medium. The shape of the write pole may be projected and reproduced on the magnetic medium during the write process. Thus, the track width can be defined by the width of the write pole at the surface facing the recording medium (i.e. air bearing surface).
One way to increase the recording capacity of medium is to decrease the width of the write pole. Sub-100 nm features (write poles having a width of less than 100 nm) can enable this increase in capacity. A write pole can be fabricated by depositing magnetic material, a hard mask and a photoresist patterning mask on a substrate. After deposition, the photoresist is patterned by photolithography. The photoresist is used to pattern the hard mask material using a material removal process such as reactive ion etching (RIE). Then, using the hard mask as a pattern, select portions of the magnetic material are removed by a milling process to form a write pole. Previously, hard masks were formed from Al2O3, SiO2, SiON, poly-Si and other similar materials. However, these hard masks are not effective for the fabrication of sub-100 nm write poles because in some cases the patterned hard masks of these materials must be thicker than 100 nm. That is, the required thickness of the hard mask was thicker than the width of the mask, resulting in decreased stability of the hard mask. The materials of these hard masks also suffered from negative contamination issues, such as contamination from oxygen ions. An improved method of forming features on magnetic transducing heads is necessary.